Gear-cutting machine.



C. A. PARSONS, A. Q. CAHNEGIE & S. S. COOK.

GEAR CUTING MACHINE.

APPLICAHON mw MAR. 2, 19m

ITV"

luhnivd Aug'. 1i, 1918.

2 SHEElSf-SHLEY 2.

Innen/tors:

C/agrles LI/zizseaw,

Q. Carire-Wie,

ely S. Coo

Atty? C. A. PARSONS, A, Q. CARNEGIE L S. S.y COOK.

GEAR CUTTING MACHHJE.

APPLICAHON mw MAH,2.19|6

1 ,274.585. Patented Aug. (s, 1918.

2 SHEETS-SHEET l.

d Inventors.-

. also to minimize the wear tion of the worm.

PATENT OFFICE.

GEAR- CUTTING MACHINE.

Original application tiled durch 25.

Specification of Letters Patent.

1913. Serial No. 756,762.

Patented Ang'. ti. l 918.

Divided and this application filed March 2,

1916. Serial N0. 81.742.

provi-menta in (ioa|'-t`uttiii;f .\lat'hinf-.. olu which thtl following.r ia a A pia'iliration.

This intention rvlrittw to nuttin-h :ont

moanV l'or rotting' tlit` tt'itli in 'mais' niiet-te'. As'ltt'li as ia tlist'rila'tl in Lettera latniit ot' tlit llliitetl States. .ti'i'anttal to ii:- .laniiari4 ll *L #marisa Y 'liile the prt-sent niathinos t'ttt tliitooth with a high oi'tler ot' at't'urat'y. a Itill iiighor degree ot' accuracy is desirable to inanrtx the Ieilt-nt operation ot' gear whetila when traite-- initting.r larg powers at high api'iiila. anil of thtl teeth. lt' 1S obvious that with the processes alrtatly atloptetl the accin'af'y of thofiniaheti wheel ('tilniot he greater than that ot' tht' parent gear of the machine h v whit'li the teeth arteut. Local irregularities in this parent gear Cause irregularities in the tettli otl the w'heela being eut whieh exactly correspond in :ingu-- lar position with those of the part-nt gear, aint wliit'h. when Sin-li wheels are in operation for the transmission of power, will `rire rist' to periotlit' vibrations. often ot' high freqiient'y, antl therefore protliit't ire ot noise. In thtl rane. for instaure. in which tht-` table y on which the work is niounttrl ia rotated liv means of a worin :intl :t worin wheel. tht` lat'.- ter being attat'ht-tl pentiianently to the table. it will be seen that the irregularities formed on the work art` a function of thtl angular position of the talihl in relation to the posi- The latter is usually fixed and since the Cutter is also usually7 in a fixed `position on the'mat'hine, and ad varices across lthe work in a direction parallel "gto .the axis of the table, there will result lines of irregularities on the finished wheelV lying in planes through the axis of the table. and therefore of the work mounted thereon.

It will be seen that irregularities so positioned will, when the Wheel is at Work, rome jat@ mesh simultaneousl;7 across the face of Y driving: shaft 27.

the wlitt-l. thnay raining' irregularities in the rfilatire rotational inotion ot' the wheel antl pinion engaging therewith. It. however. a 4-iiiall amount ot rotar \v motion relativo to thttahltx he impartial to thtI work it` will la' .at-on that thtl irroy'nlaritivav fornietl in thtJ wot-h will lio tli triliut0 i spirall)v arouml the ultimi. antl that il' tliia4 relative t'reep liv eon- :-iilor.ililt^. thaw spirala will niaht a Sinall :ingle with the plantl ot' revolution of the iilit'tll. :intl will i'oiiatapitntl \V liti Closely to eath other. willi the result that thtl pinion :ont whool will. when ,feared together. prtL N-iw a 'oiiatant relative angular velocity lititnoen tlit'ni.

'l`li'i prenant invention consists in iniprowtl moana lor tli. tillititiiig tlio irrtgriilaritimA l'orliitlil in tlitl worlt' in `apirals making a i'oniparatirtly antall angle with the plane of revioliitionE of l\aitl work. whereby the periotlie iorreapiinileni'e ot' aaitl irregularities with the irregularities ot the parent gear rotatingi` thel Haine is destroyed.

Referring to the :it-compa nying drawings- Figure 1 is a cross sectional elevation through the worlt' carrying' table and accontpaiilring.r parteof a gear Cutting machine enthotlyingir the-pri-s0nt invention.

Fig'. 2 is a part sectional plan of Fig. 1. Fig. 3 is a section on the line 3&3 of

Fig'. it.

Fig. 4 is a sitio view of that part of the inat'hino whit'h joins Fig. 1 on the right, thereof.

Fig. .3 is a plan View of that part of the nait-hintl wliit'h joins Fig'. :2 on the right..

Fig. ti ia a cross sectional View ot' Fig. l. looking' troni tlnI left.

n t'arrying the invention into effect., atcortling.i to thtl prt-Sent construction, a pri- .niary table 1 is provided. constrained to rotate about its axis by a bearing Q. in the betl nieinlier 3. Attached to the, primary table 1 is an indexing worm wheel 4. with which a driving worin 5 engages. The worin 5 is t'lrii'eh by an)v suitable in'eans from a niain The elements 4 and 5 forni a parent goal'. r

Upon the prix-nary table 1 a secundair)7 tablel (i is rotatably mounted, and is hohl down to the table 1 by dogs 7.

The work 8 is mounted upon the secondary table1 6. in any suitable manuel'.

The spindle 9? which is rotatable in suit a which Adrives through suitable able bearings co-axially with the primary table 1, carries at its upper end a worm 10. The worm 10 engages with a Worm wheel 11 mounted upon a spindle 12 carried in suit' able brackets 13, secured Ito the rimary table 1. Also mounted upon the spindle 12 isa pinion 14, which engages a spur wheel 15, carried by the spindle y16, which is mounted in one of the brackets 13. Also attached to the spindle 16 is a bevel pinion 17.

To the under side of the secondary table 6 a bevel rack 18 is secured. The pinion 17 engages with the rack 18.

To the lower end of the spindle 9 a worm Wheel 19 is secured. With the worin wheel 19 a worm 20 engages, mounted upon a spindle 21, which carries a bevel wheel 22, engaging a bevel 23, upon a spindle 24, which also carries a second bevel 25. The bevel 25 iis engaged by a bevel 26, mounted upon an yextension of the driving shaft 27.

The shaft 27 -is driven from any suitable source, and is so connected in any well known manner with the hob drive and hob feed mechanism that the proper relations are maintained to produce the required pitch of the teeth cut on the work, and also the helical angle of the teeth when helical teeth are required to be cut.

The` gearing connecting the primary and secondary tables and the gearing driving the spindle 9 are. so arranged that when the shaft 27 is driven, the tablesv 1 and 6 are rotated in the direction in which the work 8 must rotate for the cutting of the teeth on the work, while the shaft 9 is rotated in the reverse direction to the tables.

In one construction shown in the above mentioned` atent, the ,spindle 9 is stationary, and the e ect of rotating the tables about the central spindle is to cause a 'relative movement between the tables, owing to the interposed gearing. 4

,0n rotating the shaft 27 in theprcsent construction,l and thus by the worm 5 driving the tables about the spindle 9, a similar effect to the above is produced, but owing to the backward rotation of the spindle 9 there results 'a greater relative motion between the tables than that due merely to the rotation of the gear train about 9. The relative motion due to the backward rotation of El can be made of any desired amount b v var ving the pro )ortions of the gearing connectings) and 2 eferring to Figs. 4, 5 and (l which illustrate the connections to the hob and the hob feeding mechanism, it is to be noted that these are the same as those described in our patent above referred to.

The machine is driven by an electric n iotor spindle from which motion is transmitted through suitable change speed gearing c to the shaft (l. Motion is also transmitter from gearing the.`

the motor a through the shaft cl, to a cross shaft and gear wheels f, and th'rou h a reversing ear, g, to the spindle h. he gear wheels forni a chan e gear by which the helical an le of the teetli formed on the work is control ed through the usual differential in shaft d. The shaft e is a part of a connection for shifting reversing gears at g, said shaft bein operated'by the hand lever 16". The spindiie b, carries a bevel wheel, z', gearing with another bevel wheel, j, mounted on a vertical spindle k, mounted in the cutter standard l. The vertical spindle k, is provided with a feather-way m, by which its rotation is transmitted to the. cutter. The spindle h, is provided with a worm n, which engages ywith a worm wheel o, on another vertical spindle p, mounted on the cutter standard This spindle p, is threaded and when rotated causes a yvertical up or down movement of the cutter, thus moving the cutf ter across the face of the work. The cutter Vstandard-l, is provided with suitable means for being traversed' longitudinally on the bed g Vof the machine, by means of the threaded spindle r, which can be rotated by the hand wheel s.

The rotation of the shaft ll, is transmitted direct or through suitable compensating gear vas shown at 23, 24, 25, to a bevel wheel t, engaging with another bevel wheel u, on a horizontal shaft fv, carrying at its other end another bevel wheel w. This engages with a yetlfurther bevel wheel w, on a vertical shaft y, carrying at its other end a worm z engaging with a worm wheel 1*, on a shaft 2 rovided with the worm 5.

aving now described our invention, what we claim as new and desire to secure by Let? ters Patent is 1. A gear cutting machine, comprising in combination a primary table, a 'parent gear for rotating the same comprising a driving and a driven member, said driven member being attached to said table, a secondary table on which the work is carried rotatably mounted on said primary table, a train of gearing mounted upon saidV irimary table, the last member of said train ein r connected to said secondary table, a shaf co-axial with said table, gear means upon said shaft engaging the first member ot' said train, and

means to rotate said shaft, a hob, `means to tilting means to preserve correct lead rela- /tion between said hob feed and the Speed of said table. I i

2. A gear cutting machine comprisin in combination, a primary table? a. secon ary table, on which the work is carried, mounted on said primary table, a parent-gear rotating said primary table, and having a driving and a driven member, a rotating shaft coaxial with said table, a train of gearing carried by one of said tables, and connected to the other of said tables, and connected to the shaft coaxial with said tables, means for Vrotating said shaft from the driving member of said arent gear, whereby said Secondary table 1s rotated by said driving and drive member of the parent gear, but at a different rate therefrom, a hob, means` to rotate Said hob, means between said hob rotating means and said inde-X wheel rotatingr means to preserve correct indexing relation between the rotations of said hob and the rotations of said secondary table, means to feed said hob and means between said hob feeding means and said indexing wheel rotatin means to preserve correct lead relation etween said hob feed and the speed oli said table.

3. A gear cutting machine comprisingfin combination, a-primary table, means ,to rotate said table, a brit-carrying secondaryV table rotatably mounted upon said primary table, a system of gearing positioned between the two tables, and acting to produce relative motion between them, means for driv ing said System of gearing, the axis of the final driving member of said system being caused to revolve about the axis of rotation of said work carrying table. in the same directionand at a different. rate therefrom, while the first member of said s vstem is positioned coaxially with said table, and ea used to rotate, but in the opposite direction to said table, a hob, means to rotate said hob, means between said hob rotating means and Said index wheel rotating means to preserve correct indexing relation between the rotations of Said hob and tbe rotations of said secondary table, means to feed said hob and means between said hob feeding means and Said indexing wheel rotating means to pre` serve correct lead relation between said hob feed and the speed of said table.

4. A gear cutting machine comprising in combination, a primary table` a parent gear for rotatingr the same, comprising a driving and a driven member, said driven member being attached to said table, means to rotate said driving member, a secondary table on which the work is carried rotatably mounted on said primary table. a shaft coaxial with said tables, means to rotate said shaft, a train of gearing mounted on said primary table, the last member of said train being connected to-l said secondaly table, gear means upon said coaxial shaft engaging the first member of'said train, said train being caused to rotate by the motion of said primary table, and the rotation of said coaxial shaft, a hob. means to rotate said hob, means between said hob rotating means and said index wheel rotating means to preserve correet indexing relation between the rotations of said hob and the rotations of said Secondary table, means to feed said bob, and means between said hob feeding means and said indexing wheel rotating means to preserre Correct lead relation between said hob feed and the speed of' said table.

5. A gear cutting machine comprising in combination. a work carr \'ing table, an index wheel, a gear train. means to rotate the first member of said train, the final member of said traii being connected to said table, a member of said train between said first mem- 'ber and said final member being Connected t0 "said 'index wheel, a hob, means to rotate said hob. means between said hob rotating means am said index wheel rotatingr means to pieserre correct indexing relation between the rolationsofsaid holland fl1elota tions of said work carrying table, means to feed said hob, and means between said hob feeding means and said indexing wheel rotating means to preserve correct lead relation between said hob feed and the speed of said table.

t3. A gear cutting machine comprising in combination` a \\'ork('a1'rying fable, an index wheel. means to rotate said index wheel, a gear train, the final member of said train being connected to said table` a member of said train between the first member and final member being carried by said index wheel, and the first member of said train being ronneeted to said index wheel driving means, to be operated thereby, a hob, means to rotate said hob, means between said hob rotating means and said index wheel rotating means to preserve cori-eri indexing relai ion between tbe rotations of said hob and the rotation? of said urli-carrying table` means to feed said hob. and means between said hob feeding means and said indexing wheel rotating means to preserve correct lead rel-ation between said hob feed and the speed of said table.

Tn test imony whereof, we have affixed our signatures.

CHARLES AlifililtNON PARSONS. Ahliltlll) QUIN'I'IN GAltNEGIIl. STANLEY SMITH 000K. 

